Elon Musk has made new comments about the Tesla Semi program, its upcoming electric prime mover, claiming that the vehicle will eventually have up to 1,000 km  of range on a single charge.

Musk says that this range is going to be achieved, thanks to Tesla’s new in-house battery cells and battery pack technology.

When launching the Tesla Semi in 2017, the automaker claimed that the production versions of Tesla Semi,  a class 8 truck with a 36.4 tonne (80,000lb) capacity, would boast a 600km range for a price of  $US150,000 and or an 800km range option for  $US180,000.

However, Musk has said that the company has found opportunities to extend that range during testing. claiming that theTesla Semi will now have closer to 100okm of range.

Musk elaborated on the range of the Tesla Semi in new comments during a recent interview.

“Getting a range of let’s say 500 km is I think quite easy, trivial to be frank, for a semi truck and this is assuming a truck that is pulling a load of 40 metric tonnes. If you want, for long-range trucking, you can take the range up to, we think, easily 800 km, and we see a path over time to 1,000 km range for a heavy duty truck,” said Musk

The capacity of the Tesla Semi is of course a vital question because  cargo capacity affects the trucks profitability.

This has been an issue for electric trucks largely due to the weight of the battery pack.

Musk addressed this and  admitted  that the Tesla Semi might have to give up a tonne of cargo capacity to the weight of the power pack

“You are able to carry basically the same cargo as a diesel truck,” said Musk

“However we think that maybe there’s one tonne penalty at this point, however we think that we can make the reduction in cargo capacity less than one-tonne and think longer term it’s going to be zero cargo reduction for our electric trucks,” said Musk.

Musk also confirmed that the Tesla Semi is going to use Tesla’s new 4680 cells and the new structural battery pack design that Tesla unveiled at its Battery Day event.

He said that those kind of ranges are achievable for an electric semi truck at “around 300 Wh/kg” of energy density at the cell level — hinting at the energy density of Tesla’s new cells.